Spring bar



May 116, 1950 J. 5. FEINER ET AL SPRING BAR Filed June 26, 1946INVENTORS JACOB S. ffl/VER ZA WRENCE 1.. STONZ- A TTORNEX Patented May16, 1950 its s'rAss SPRING BAR Application June 26, 1946, Serial No.619,507

3 Claims. 1

This invention relates to spring bars for wrist watches, bracelets andother items of jewelry, and more particularly, spring bars of the typehaving a hollow tube, a trunnion slidably received at one or both endsof the tube and a compression spring within the tube forcing thetrunnion or trunnions outwardly.

One object of the invention is to provide a spring bar of the typedescribed having component parts, more particularly, trunnions, whichare facilelyand quickly assembled in position. In spring bar-sheretofore made the trunnions are not symmetrical so that each trunnionis required to be handled separately and examined carefully in orderthat its prop-er end be inserted in the tube. An allied object of theinvention is to provide a spring oar construction in which the trunnionsare symmetrical so that either end may be inserted in the tubeindiscriminately without examination. Ihis lends itself to simple,accurate and fast assembly, which may be automatic or semi-automatic,the improved trunnions being dumped into a hopper and individually fedfrom the mouth thereof.

A. further object of the invention is to provide a spring bar of thetype described having a structure, particularly, that of the trunnion,which will eliminatewobble and play of the parts and reduce stressrepetition, fatigue and consequent failure. An allied object is toprovide a trunnion having an increased bearing surface in the form of adouble bearing surface comprising two widely spaced-apartbearingsurfaces separated by a central recessed portion. A further object is toprovide a trunnion having double bearing surfaces separated by a centralannular recess adapted to cooperate with one or more identatic-ns on thetube inwardly projected into the annular recess to retain the trunnionwithin the tube.

For the attainment of the foregoing and such other objects of inventionas may appear or be pointed out herein we have shown several embodimentsof our invention in the accompanying drawing, wherein:

Figure l is a top view of one form of improved spring bar, showingfragmentary portion of the jewelry item to which it is applied;

Figure 2 is a top view of the improved trunnion used in the spring barof Figure 1;

Figure 3 is a top view,partially sectionalized, of a portion of a secondform of spring bar, employing the improved trunnion of Figure 2;

Figure dis a top view-partially'sectionalized,

of a portion of a third form of improved spring bar;

Figure 5 is a top view of the improved trunnion used in the spring barofFigure 4;

Figure 6 is a top view,'partially sectionalized, showing a fourth formof improved springbar, showing a portion of the jewelry item towhich itis applied; and

Figure '7 is a tcpview of the improved trunnion used in the spring'barof Figure 6.

The type of spring bar to which this invention relates includes a tube,such as I, Figure 1, which is to be removably secured'between a pair ofspaced supportingeiements, such as the spaced lugs 9, projecting fromthe wrist watch 8 or other item of jewelry. Spaced lugs 9 are providedwith aligned openings i on their inner, opposing faces. As showninFigure 1, openings i do not extend through to the outer faces of thelugs; this form of spring bar connection, referred to as blind," ispreferred because an opening on the outer faces of the lugs would martheir appearance and interfere with any design engraved thereon. In somecases, known as through connections, apertures, such as '5; Figure '6,extend through the lugs.

The spring bar is further provided with a reduced stein projectingoutwardly at each end of its tube and adapted to be received within theopenings (I, Figure l, 6, Figure 6) of the lugs. At least one of thestems is an integral part of an element known as a trunnion which isslidably retained within the tube and spring pressed to project its stemoutwardly of the encasing tube. The trunnion permits the spring bartobeinserted in, and removed from, itssecured position between the lugs, byforcing the trunnion inwardly against the spring toengage its stem, orto free its stem from engagement, in the lug opening. In some cases oneof the stems is formed out of the tube material or may be fixedlysecured at one end. of the tube. In other cases, a trunnion is providedat each end of the tube. This is the form illustrated in the drawing.Also, the invention applies equally to blind connections, Figure l, orthrough connections, Figure 6.

In Figure 1, trunnion I0, one at each end of tube i, shown inFigure 2,has a central portion comprising a pair of intermediate cylindricalportions ll, l2, separated by a central annular recess l3, presentingbearing surfaces slidably engaged with the interior surface of tube I.The trunnions Ill, [0 areurged outwardly by a helical compression spring5 within the tube but are retained withinthe tube against the force ofthe spring by one or more projections 4 formed by indenting the tubematerial inwardly. Indentations 4 project into the annular recess I3 ofthe trunnions and are abutted by the spring-pressed trunnions at theannular shoulder defining the inner wall of cylindrical portions I I, I2and one wall of annular recess I3. Projecting outwardly of cylindricalportions II, I2 and centrally located on the longitudinal axis L-L,Figure 2, of the spring bar are reduced stems I5, I4, respectively. Oneof the stems, such as the stem I4 of the trunnion at the right end ofthe tube, Figure 1, is received in the opening 'I of the supporting lug9. The indentations 4 are positioned at a predetermined distance fromthe ends of the tube so that a stem, such as the stem I4 of the righttrunnion, will project outwardly beyond the tube a predetermined extentso that it may be readily fitted into the opening I, the spring barbeing then held securely between the spaced lugs 9, 9 by the compressiveforce of spring 5, and so that the spring bar may be removed from thelugs by forcing the trunnion into the tube, against the outward urgencyof the compression spring, to clear the stem from engagement withopening I.

The dimension of the cylindrical portion, such as the cylindricalportion I2 of the trunnion at the right end of the tube, Figure 1, andthe said predetermined position of indentations 4 are such that apredetermined part of the cylindrical portion, designated I2 in Figure1, extends beyond the end of the tube. It is required that thecylindrical portion extend beyond the end of the tube so that the outerwall of the cylindrical portion may abut the inner wall of supportinglug 9 at a point beyond the end of the tube, to enable a blade or otherinstrument to be forced between the abutting walls. The distance ofoutward extension I2 of the cylindrical por tion is such that thetrunnion may be forced into the tube a sufficient distance-limited bythe abutment of the blade or instrument with the end of the tube-toenable the stem to be cleared from the opening I.

The trunnion of the improved spring bar, such as the trunnion I0, Figure2, is made symmetrical about a plane SS transversely disposed, i. e.,normally to the longitudinal axis L-L of the trunnion, at a centralpoint thereof. By reason of the symmetrical formation of trunnion I0,its stems i4, I5 are identically dimensioned and equidistanced from theplane of symmetry S-S, and its cylindrical portions II, I2 are likewiseidentically dimensioned and equi-distanced from S-S; finally, annularrecess I3 is centrally divided by the plane of symmetry SS. As a resultof the said symmetrical formation of trunnion I9, either end may beindiscriminately inserted in the tube of the spring bar. For example,one trunnion I is inserted into the tube, Figure 1, at the right thereofwith stem I and cylindrical portion Ii foremost so stem I 4 and anextent I2 of cylindrical portion I2 project beyond the tube. It isimmaterial which end of the trunnion is inserted in the tube; thetrunnion could as well have been inserted with stem I4 and cylindricalportion I2 foremost, as is shown in connection with the trunnion at theleft of the tube, in which case stem I5 and extent II of cylindricalportion II project beyond the tube. Irrespective of which end of thetrunnion is inserted in the tube, the stem (whether stem I4 at theright, Figure '1, or stem I5 at the left) projecting from the tube willbe identically dimensioned and will project the same distance beyond thetube; like- 4 wise, the extent of cylindrical portion (whether I2 at theright, Figure 1, or I I at the left) projecting from the tube will bethe same.

The helical spring 5 of the improved spring bar is such that thediameter of its central, inner space is sufficiently large to enable thestern I4, I5 of the trunnion to be received therein, as shown in Figure1, so that either end of the trunnion may be inserted in the tube andthe inserted stem will be received in the inner space of the spring. Theretaining projections 4 may be indented in the tube wall after thetrunnion or trunnions have been inserted in the tube, or the tube may befirst indented and the trunnion or trunnions subsequently inserted, thetube material having sufiicient yieldability or resilience to permit theleading cylindrical portion lI, I2 to be forced inwardly beyond theprojections 4.

The improved symmetrical trunnion III of Figure 2 may be used in asecond type of spring bar shown in Figure 3 wherein the end of the tubeI6 is crimped or spun over at I! to be received within the annularrecess I3 of the trunnion to retain it within the tube against theurgency of compression spring 5 and with stem I5 as well as onecylindrical portion II entirely beyond the end of the tube. The partsare designed so that the stem and the cylindrical portion will bedisposed at predetermined positions from the end of the tube. By reasonof the symmetrical formation of the trunnion either end may be insertedin the tube so that at all times a stem (whether stem I4 or I5) and acylindrical portion (whether I2 or II) will be disposed at the saidpredetermined positions.

A third type of spring bar is shown in Figure 4 wherein the trunnion 20has a central cylindrical portion 23 on both sides of which areannularly recessed or reduced portions 2i, 22, and reduced stems 24, 25extending from annularly reduced portions 2i, 22. Central cylindricalportion 23 is in slidable engagement with the inner surface of tube I6,and the trunnion retained within the tube by crimping or spinning theend I! of the tube over the central cylindrical portion 23 of thetrunnion, the inwardly turned end I! being received in the annular spaceprovided by annularly reducing portions 2|, 22. The reduced portions 2|,22 thus enables the end of the tube to be crimped over, and alsoprovides a part projecting beyond the end of the tube, which projectingpart functions in inserting and removing the spring bar as more fullyexplained with reference to projecting part I 2 Figure 1.

Trunnion 28, Figures 4 and 5, is symmetrical about central transverseplane SS, Figure 5, so that either end of the trunnion may beindiscriminately inserted in the tube and there will, at all times,project from the end of the tube a stem (whether 24 or 25) of identicaldimension and disposed at the same predetermined distance from the endof the tube, and a predetermined extent of a reduced portion (whether 22or ZI).

The type of spring bar illustrated in Figure 1, Figure 3, and Figure 4may be used in either the blind connection (described above withreference to Figure 1)by reason of the projected portion of the trunnion(such as portion I2 Figure 1, the cylindrical portion I I, Figure 3, orthe extended portion of RI, Figure 4)-or in the through connection(described below with reference to Figure 6). The fourth type of springbar shown in Figure 6 employing the improved trunnion 30 shown in Figure'7 can be used only with 76 the through connection (as shown in Figure6) as it can be removed only by forcing the trunnion into the tube byapplying a force at the end of the stem, such as 34, exposed at theouter face of supporting lug 9. Trunnion 30 has a central cylindricalportion 33 and reduced stems 34, 35 on each side thereof and is retainedwithin the tube l6 by crimped end I! thereof. Trunnion 30 is symmetricalabout central transverse plane S-S so that either end of the trunion maybe indiscriminately inserted in the tube to project a stem (whether 34or 35) of identical dimensions beyond the end of the tube.

A troublesome objection to spring bars as heretofore made is the wobbleand play of theparts,

particularly at the trunnion, which causes stress repetition, fatigueand consequent wear and failure and loosening of the spring bar. We haveovercome this objection by providing a spring bar, see Figure 1, inwhich trunnion ID has increased bearing surface at the spacedcylindrical portions ll, l2; the provision of spaced bearing surfaces,one at cylindrical portion H and the other at cylindrical portion 12,reduces wobble and play and at the same time utilizes the central recessI3 for retaining the trunnion within the tube, by the indentedprojections 4, as already described.

We claim:

1. An improved trunnion for use in a spring bar of the type having atube, an inwardly extending stop on the tube and a trunnion at at leastone end of said tube, said improved trunnion comprising a centralportion annularly recessed to present a pair of spaced intermediatecylindrical portions, at least one of the said cylindrical portionsbeing adapted for slidable engagement with the interior surface of thetube and adapted to engage said stop, said central recessed portionbeing proportioned for receiving therein said stop, and a reduced stemextending outwardly from each of said cylindrical portions, said stems,cylindrical portions and annular recess being symmetrical about acentral transverse plane through the improved trunnion, whereby eitherend of the improved trunnion may be inserted in the said tube to presenta stern of predetermined dimensions projecting a predetermined extentoutwardly of the tube.

2. A spring bar of the class described comprising a tube, a trunnion atat least one end thereof, and a compression spring within the tubebearing against the trunnion and urging it outwardly, said trunnionhaving a central portion annularly recessed to present a pair of spacedintermediate cylindrical portions and a 05 reduced stem extendingoutwardly from each of said cylindrical portions, projections indentedinwardly of the tube material and received within the said annularrecess of the trunnion to retain the same within the tube against theurgency of said compression spring, said projections being disposedrelative to the end of the tube such that the said stem will project apredetermined distance beyond the tube and a predetermined extent of thecylindrical portion will project beyond the tube, said trunnion beingsymmetrical about a central transverse plane whereby either end of thetrunnion may be inserted in the tube to project a stem at the saidpredetermined distance, and to project the said predetermined extent ofa cylindrical portion, beyond the end of the tube.

3. A spring bar of the class described comprising a tube, a trunnion atat least one end thereof, and a compression spring within the tubebearing against the trunnion and urging it outwardly, said trunnionhaving a central portion annularly recessed to present a pair of spacedcylindrical portions and a reduced stem extending outwardly from each ofsaid cylindrical portions, projections indented inwardly of the tubematerial and received within the said annular recess of the trunnion toretain thesame within the tube against the urgency of said compressionspring, said projections being disposed relative to the end of the tubesuch that the said stem will project a predetermined distance beyond thetube, the said cylindrical portions presenting double bearing surfacesslidably engaged with the interior surface of the tube, and spaced apartto increase the effective bearing surface of the trunnion, said trunnionbeing symmetrical about a central transverse plane.

JACOB S. FEINER. LAWRENCE L. STONE.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,194,484 Depollier Aug. 15, 19161,744,685 Nittel Jan. 21, 1930 1,745,565 Wittman Feb. 4, 1930 2,063,733Greenberg Dec. 8, 1936 2,157,408 Greenberg May 9, 1939 2,392,092Konikofi Jan. 1, 1946 FOREIGN PATENTS Number Country Date 125,540Switzerland July '7, 1928 130,728 Switzerland Mar. 1, 1929

